NAME
strcspn — get the
length of a complementary substring
SYNOPSIS
#include
<string.h>
size_t strcspn(const char *s1, const char *s2);
DESCRIPTION
[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2024 defers to the ISO C standard.
The strcspn () function shall
compute the length (in bytes) of the maximum initial segment of the string
pointed to by s1 which consists entirely of bytes
not from the string
pointed to by
s2.
[CX] The strcspn ()
function shall not change the setting of errno on valid
input.
RETURN VALUE
The strcspn () function shall return the
length of the computed segment of the string pointed to by
s1; no return value is reserved to indicate an error.
ERRORS
No errors are defined.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
XBD <string.h>
CHANGE HISTORY
First released in Issue 1. Derived from Issue 1 of the SVID.
Issue 5
The RETURN VALUE section is updated to indicate that
strcspn () returns the length of
s1, and not s1 itself as was previously
stated.
Issue 6
The Open Group Corrigendum U030/1 is applied. The text of the RETURN VALUE section is updated to indicate that the computed segment length is returned, not the s1 length.
Issue 8
Austin Group Defect 448 is applied, adding a requirement that
strcspn () does not change the setting of
errno on valid input.